Systems and methods for multiple redundant transmissions for user equipment cooperation

ABSTRACT

Aspects of the present application provide methods and device for use in User Equipment (UE) cooperation. UE cooperation may include the cooperating UEs (CUEs) forwarding traffic to or from one or more target UEs (TUEs) with redundant signal transmissions or receptions. Methods involve a base station transmitting configuration information to at least one cooperative user equipment (CUE) and to a target user equipment (TUE). The configuration information includes an indication of resources for a sidelink (SL) transmission and a redundancy parameter for the SL transmission. The SL transmission is a transmission for the at least one CUE to forward a packet intended for the TUE. The base station also transmits the packet intended for the TUE, to a plurality of UEs comprising the at least one CUE and the TUE.

RELATED APPLICATIONS

This application claims the benefit of priority of U.S. ProvisionalPatent Application 62/835,748 filed on Apr. 18, 2019, which is herebyincorporated by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates generally to wireless communications, andin particular embodiments, to User Equipment (UE) cooperation, inparticular multiple redundant transmissions.

BACKGROUND

In some wireless communication systems, user equipments (UEs) wirelesslycommunicate with a base station (or gNB) to send data to the basestation and/or receive data from the base station. A wirelesscommunication from a UE to a base station is referred to as an uplink(UL) communication. A wireless communication from a base station to a UEis referred to as a downlink (DL) communication. A wirelesscommunication from a first UE to a second UE is referred to as asidelink (SL) communication or device-to-device (D2D) communication.

Resources are required to perform uplink, downlink and sidelinkcommunications. For example, a base station may wirelessly transmitdata, such as a transport block (TB), to a UE in a downlink transmissionat a particular frequency and over a particular duration of time. Thefrequency and time duration used are examples of resources.

UE cooperation has been proposed to enhance reliability,throughput/capacity, and coverage. For example, UE cooperation can beused to provide diversity in space, time and frequency, and increase therobustness against fading and interference. In UE cooperation, SLcommunications are used to establish joint UE reception, where some ofthe UEs, referred to as cooperating UEs (CUEs), act as relays for otherUEs, referred to as target UEs (TUEs) to improve system throughput andcoverage. However, joint UE reception using SL communications can alsoincrease the complexity of the network communications, such as forhybrid-automatic repeat request (HARQ) signaling. The HARQ mechanism isa link adaptation technique that can improve communications forerroneous data packets in wireless communication networks.

SUMMARY

According to a first aspect of the disclosure, there is provided amethod that includes: transmitting, by the base station, configurationinformation to at least one cooperative user equipment (CUE) and to atarget user equipment (UE), the configuration information comprising anindication of resources for a sidelink (SL) transmission and aredundancy parameter for the SL transmission, the SL transmission forthe at least one CUE to forward a packet intended for the TUE. Themethod further includes transmitting, by the base station, the packetintended for the TUE, to a plurality of UEs comprising the at least oneCUE and the TUE.

In some embodiments, transmitting configuration information to the atleast one CUE and to the TUE includes: the base station transmitting tothe at least one CUE: an identification of the TUE that the at least oneCUE is to aid by forwarding the packet intended for the TUE, and anidentification of initial or redundant transmission signals associatedwith a specific CUE and a number of repetitions; and the base stationtransmitting to the TUE: an identification of initial or redundanttransmission signals associated with the TUE and a number ofrepetitions.

In some embodiments, the configuration information further comprises oneor more of: a diversity scheme to be used for transmission by the atleast one CUE; a forwarding scheme to be used for transmission by the atleast one CUE; and a diversity scheme to be used for transmission by theTUE.

In some embodiments, the resources for the SL transmission compriseresources for an acknowledgment transmission from the TUE to the atleast one CUE.

In some embodiments, configuration information that is the same formultiple UEs of the plurality of UEs is transmitted using groupcast,multicast or broadcast transmissions; or configuration information thatis unique to a given UE of the plurality of UEs is transmitted usingunicast transmissions.

In some embodiments, transmitting the configuration informationcomprises at least one of: transmitting the configuration information ina pre-configured manner; transmitting the configuration informationsemi-statically; and transmitting the configuration informationdynamically.

In some embodiments, transmitting the configuration informationcomprises at least one of: transmitting the configuration information inradio resource control (RRC) signaling; transmitting the configurationinformation in downlink control information (DCI) signaling or sidelinkcontrol information signaling (SCI), or both; and transmitting theconfiguration information in RRC and DCI/SCI signaling.

In some embodiments, the redundancy index is an identification ofinitial or redundant version transmission signals to be used for atleast one of transmission by the at least one CUE or by the TUE is oneof: chase combining (CC) hybrid automatic repeat request (HARQ); andincremental redundancy (IR) HARQ.

In some embodiments, the identification of initial or redundant versiontransmission signals to be used for at least one of transmission by theat least one CUE or by the TUE is a redundancy index.

In some embodiments, the diversity scheme to be used for at least one oftransmission by the at least one CUE or by the TUE is one of: anAlamouti diversity scheme; and a cyclic delay diversity (CCD) scheme.

In some embodiments, the forwarding scheme to be used for at least oneof transmission by the at least one CUE is one of: a decode and forward(DF) scheme; an amplify and forward (AF) scheme; a quantization andforward (QF) scheme; and a compress and forward (CF) scheme.

In some embodiments, the method further includes transmitting a packetthat is intended for the TUE via unicast, groupcast, multicast orbroadcast to the plurality of UEs.

According to a second aspect of the disclosure, there is provided adevice that includes a processor and a computer-readable medium havingstored thereon computer-implemented instructions. Thecomputer-implemented instructions, when executed by the processor causethe device to transmit configuration information to at least onecooperative user equipment (CUE) and to a target user equipment (TUE),the configuration information comprising an indication of resources fora sidelink (SL) transmission and a redundancy parameter for the SLtransmission, the SL transmission for the at least one CUE to forward apacket intended for the TUE. The computer-implemented instructions, whenexecuted by the processor further cause the device to transmit thepacket intended for the TUE, to a plurality of UEs comprising the atleast one CUE and the TUE.

In some embodiments, the instructions further cause the device to:transmit to the at least one CUE: an identification of the TUE that theat least one CUE is to aid by forwarding the packet intended for theTUE, and an identification of initial or redundant transmission signalsassociated with a specific CUE and a number of repetitions; and transmitto the TUE: an identification of initial or redundant transmissionsignals associated with the TUE and a number of repetitions.

According to a third aspect of the disclosure, there is provided amethod that includes: receiving, by a cooperative user equipment (CUE),configuration information including an indication of resources for asidelink (SL) transmission and a redundancy parameter for the SLtransmission, the SL transmission for the at least one CUE to forward apacket intended for a target user equipment (TUE); receiving, by theCUE, a packet from the at least one base station and intended for theTUE; forwarding, by the CUE, the packet intended for the TUE, forwardingby the CUE, the packet intended for the TUE, by transmitting up to amaximum number of configured repetitions N, an n^(th) redundant signalversion having a respective modulation and coding scheme (MCS), wheren=1 to N.

In some embodiments, the configuration information includes anidentification of the TUE that the CUE is to aid by forwarding thepacket intended for the TUE; SL transmission resources available to beused by the CUE for forwarding the packet intended for the TUE; anidentification of initial or redundant transmission signals associatedwith the CUE and a number of repetitions.

In some embodiments, the method further comprises the CUE receiving theidentification of the TUE from the TUE: during initial UE cooperationsetup; or during a request procedure that the TUE asks for help from theCUE.

In some embodiments, the configuration information further includes oneor more of: a diversity scheme to be used for transmission by the atleast one CUE; and a forwarding scheme to be used for transmission bythe at least one CUE.

In some embodiments, the resources for the SL transmission includesresources for an acknowledgment transmission from the TUE to the atleast one CUE.

In some embodiments, forwarding the packet comprises one of: forwardingthe packet using one or more repetitions on at least one configuredgrant transmission resource; forwarding the packet using one or morerepetitions on at least one configured grant transmission resources,together with sidelink control information (SCI) for configuring one ormore of: the redundant version signal information for at least onerepetition of the packet, an HARQ ID associated with the packet,diversity scheme, forwarding scheme, TUE ID/designation ID in the UCgroup and MCS; and forwarding the packet using one or more repetitionson at least one transmission resource that is dynamically configured,together with sidelink control information (SCI) for configuring one ormore of: the redundant version signal information for at least onerepetition of the packet, an HARQ ID associated with the packet,diversity scheme, forwarding scheme, TUE ID/designation ID in the UCgroup and MCS.

In some embodiments, forwarding the packet is performed using at leastone of unicast, groupcast, multicast, and broadcast transmissions.

In some embodiments, forwarding the packet on the at least oneconfigured grant transmission resource comprises forwarding, for an nthrepetition, an nth signal version, n being previously configured, andusing a previously configured modulation and coding scheme (MCS).

In some embodiments, a hybrid automatic repeat request (HARQ) identifier(ID) of the repetition is determined implicitly based on previouslyconfigured transmission resources.

In some embodiments, the method further includes the CUE receiving apositive or negative acknowledgment of one or more of the repetitions ofthe packet on a configured grant transmission resource.

In some embodiments, forwarding the packet on the at least oneconfigured grant transmission resource, together with SCI, comprisesforwarding, for an nth repetition, an nth signal version using amodulation and coding scheme (MCS) and having a hybrid automatic repeatrequest (HARQ) identifier (ID), wherein the value of n, MCS and HARQ IDfor the repetition are included in the SCI.

In some embodiments, the method further includes the CUE receiving apositive or negative acknowledgment of one or more of the repetitions ofthe packet on a configured grant transmission resource.

In some embodiments, forwarding the packet on the at least onetransmission resource, together with SCI, comprises forwarding, for annth repetition, an nth signal version using a modulation and codingscheme (MCS) and having a hybrid automatic repeat request (HARQ)identifier (ID), wherein the value of n, MCS and HARQ ID for therepetition are included in the SCI and wherein the transmission resourcehas been dynamically configured.

In some embodiments, the method further includes the CUE receiving apositive or negative acknowledgment of one or more of the repetitions ofthe packet on a transmission resource that has been pre-configured ordynamically configured.

In some embodiments, the identification of initial or redundanttransmission signals to be used for at least one of transmission by theCUE is one of: chase combining (CC) hybrid automatic repeat request(HARQ); and incremental redundancy (IR) HARQ.

In some embodiments, the identification of initial or redundant versiontransmission signals to be used for at least one of transmission by theCUE is a redundancy index.

In some embodiments, a diversity scheme used for repetitions of thepacket received by the TUE or for the positive or negativeacknowledgment of one or more of the repetitions of the packet is oneof: an Alamouti diversity scheme; and a cyclic delay diversity (CCD)scheme.

In some embodiments, a forwarding scheme used for repetitions of thepacket received by the TUE or for the positive or negativeacknowledgment of one or more of the repetitions of the packet is oneof: a decode and forward (DF) scheme; an amplify and forward (AF)scheme; a quantization and forward (QF) scheme; and a compress andforward (CF) scheme.

According to a fourth aspect of the disclosure, there is provided adevice including a processor and a computer-readable medium havingstored thereon computer-implemented instructions. Thecomputer-implemented instructions, when executed by the processor, causethe device to: receive configuration information comprising anindication of resources for a sidelink (SL) transmission and aredundancy parameter for the SL transmission, the SL transmission forthe at least one device to a forward packet intended for a target userequipment (TUE); receive the packet from a base station and intended forthe TUE; forward the packet intended for the TUE, by transmitting up toa maximum number of configured repetitions N, an n^(th) redundant signalversion having a respective modulation and coding scheme (MCS), wheren=1 to N.

In some embodiments, the configuration information includes: anidentification of the TUE that the device is to aid by forwarding thepacket intended for the TUE; SL transmission resources available to beused by the device for forwarding the packet intended for the TUE; andan identification of initial or redundant transmission signalsassociated with the device and a number of repetitions.

In some embodiments, the instructions further cause the device toforward the packet by one of: forwarding the packet using one or morerepetitions on at least one configured grant transmission resource;forwarding the packet using one or more repetitions on at least oneconfigured grant transmission resource, together with sidelink controlinformation (SCI) for configuring one or more of: the redundant versionsignal information, an HARQ ID associated with the packet, diversityscheme, forwarding scheme, feedback related info and resourceallocation/indication, CUE/source ID in the UC group, TUE ID/designationID in the UC group and MCS; and forwarding the packet using one or morerepetitions on at least one transmission resource that is dynamicallyconfigured, together with sidelink control information (SCI) forconfiguring one or more of: the redundant version signal information, anHARQ ID associated with the packet, diversity scheme, forwarding scheme,TUE ID/designation ID in the UC group and MCS.

In some embodiments, the instructions further cause the device toreceive a positive or negative acknowledgment of one or more of therepetitions of the packet: on a configured grant transmission resource;or on a transmission resource that has been pre-configured ordynamically configured.

According to a fifth aspect of the disclosure, there is provided amethod including: transmitting, by a target user equipment (TUE), anidentification of the TUE to at least one cooperative user equipment(CUE); receiving, by the TUE, configuration information including: anindication of resources for a sidelink (SL) transmission and aredundancy parameter for the SL transmission, the SL transmission forthe at least one CUE to forward a packet intended for the TUE;receiving, by the TUE, the packet intended for the TUE, the packetincluding: for up to a maximum number of configured repetitions N, n=1to N, an nth signal version having a respective modulation and codingscheme (MCS); and decoding, by the TUE, the packet using one or morereceived repetitions of the packet from one or more CUEs.

Additionally, or alternatively, the TUE may provide an identification ofthe TUE to at least one CUE during initial UE cooperation setup orduring a request procedure that the TUE asks for help from the CUE.

In some embodiments, the configuration information includes: SLtransmission resources available to be used by the TUE for receivingpackets; and an identification of initial or redundant transmissionsignals associated with the TUE and a number of repetitions.

In some embodiments, the configuration information further includes adiversity scheme to be used for transmission by the TUE.

In some embodiments, the resources for the SL transmission includeresources for an acknowledgment transmission from the TUE to the atleast one CUE.

In some embodiments, the packet includes one of: receiving the packet asone or more repetitions on at least one configured grant transmissionresource from one or more CUEs; receiving the packet as one or morerepetitions on at least one configured grant transmission resource fromone or more CUEs, together with sidelink control information (SCI) forconfiguring one or more of: the redundant version signal information forat least one repetition of the packet, an HARQ ID associated with thepacket, diversity scheme, forwarding scheme, TUE ID/designation ID inthe UC group and MCS; and receiving the packet as one or morerepetitions on at least one transmission resource that is dynamicallyconfigured from one or more CUEs, together with SCI for configuring oneor more of: the redundant version signal information for at least onerepetition of the packet, an HARQ ID associated with the packet,diversity scheme, forwarding scheme, TUE ID/designation ID in the UCgroup and MCS.

In some embodiments, receiving the packet on the at least one configuredgrant transmission resource comprises receiving, for an nth repetition,an nth signal version, n being previously configured, the nth signalversion being modulated and coded using a previously configuredmodulation and coding scheme (MCS).

In some embodiments, a hybrid automatic repeat request (HARQ) identifier(ID) is determined implicitly based on previously configuredtransmission resources.

In some embodiments, the method further includes the TUE transmitting apositive or negative acknowledgment of one or more of the repetitions ofthe packet on the configured grant transmission resource.

In some embodiments, receiving the packet on the at least one configuredgrant transmission resource, together with SCI, comprises receiving, foran nth repetition, an nth signal version modulated and coded using amodulation and coding scheme (MCS) and having a hybrid automatic repeatrequest (HARQ) identifier (ID), wherein the value of n, MCS and HARQ IDfor the repetition are included in the SCI.

In some embodiments, the method further includes the TUE transmitting apositive or negative acknowledgment of one or more of the repetitions ofthe packet on configured grant transmission resource.

In some embodiments, receiving the packet on the at least onetransmission resource, the packet including SCI, comprises receiving,for an nth repetition, an nth signal version modulated and coded using amodulation and coding scheme (MCS) and having a hybrid automatic repeatrequest (HARQ) identifier (ID), wherein the value of n, MCS and HARQ IDfor the repetition are included in the SCI and wherein the transmissionresource has been dynamically configured.

In some embodiments, the method further includes the TUE receiving apositive or negative acknowledgment of one or more of the repetitions ofthe packet on a transmission resource that has been pre-configured ordynamically configured.

According to a sixth aspect of the disclosure, there is provided adevice including a processor and a computer-readable medium havingstored thereon computer-implemented instructions. Thecomputer-implemented instructions, when executed by the processor, causethe UE to: receive configuration information comprising an indication ofresources for a sidelink (SL) transmission and a redundancy parameterfor the SL transmission, the SL transmission for at least onecooperative user equipment (CUE) to forward a packet intended for thedevice; receive the packet intended for the device, the packetcomprising for up to a maximum number of configured repetitions N, n=1to N, an nth signal version having a respective modulation and codingscheme (MCS); and decode the packet using one or more receivedrepetitions of the packet from one or more CUEs.

In some embodiments, the configuration information includes at least oneof: SL transmission resources available to be used by the TUE forreceiving packets; an identification of initial or redundanttransmission signals associated with the TUE and a number ofrepetitions; and a diversity scheme to be used for transmission by theTUE.

In some embodiments, the instructions further cause the device toreceive the packet by one of: receiving the packet as one or morerepetitions on at least one configured grant transmission resource fromone or more CUEs; receiving the packet as one or more repetitions on atleast one configured grant transmission resource from one or more CUEs,together with sidelink control information (SCI) for configuring one ormore of: the redundant version signal information, an HARQ ID associatedwith the packet, diversity scheme, forwarding scheme, TUE ID/designationID in the UC group and MCS; and receiving the packet as one or morerepetitions on at least one transmission resource that is dynamicallyconfigured from one or more CUEs, together with SCI for configuring oneor more of: the redundant version signal information, an HARQ IDassociated with the packet, diversity scheme, forwarding scheme, TUEID/designation ID in the UC group and MCS.

In some embodiments, the instructions further cause the device totransmit a positive or negative acknowledgment of one or more of therepetitions of the packet on the configured grant transmission resource.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present embodiments, and theadvantages thereof, reference is now made, by way of example, to thefollowing descriptions taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 is a schematic diagram of a communication system in whichembodiments of the disclosure may occur.

FIGS. 2A and 2B are block diagrams of an example user equipment and basestation, respectively.

FIG. 3 is a block diagram illustrating an example of a network servingtwo UEs according to an aspect of the present disclosure.

FIG. 4 is a schematic diagram of communications between a base stationand multiple user equipment in a UE group according to an embodiment ofthe present disclosure.

FIGS. 5A, 5B, 5C and 5D are examples of four different arrangements ofunicast and multicast transmissions on Uu links and sidelinks (SLs),according to embodiments of the present disclosure.

FIG. 6 is a signaling diagram showing an example of how a base stationmay send configuration information to cooperating UEs (CUEs) and targetUEs (TUEs) according to an embodiment of the present disclosure.

FIG. 7A is a signaling diagram showing an example of how one or moreCUEs may send packet information to at least one TUE on a configuredgrant transmission resource without sidelink control information (SCI)according to an embodiment of the present disclosure.

FIG. 7B is a signaling diagram showing an example of how one or moreCUEs may send packet information to at least one TUE on a configuredgrant transmission resource with SCI according to an embodiment of thepresent disclosure.

FIG. 7C is a signaling diagram showing an example of how one or moreCUEs may send packet information to at least one TUE on a dynamicallyconfigured transmission resource using SCI according to an embodiment ofthe present disclosure.

FIG. 8 is a schematic diagram showing an example of redundant signalingfor packet transmission by a base station, packet forwarding by multipleCUEs to multiple TUEs and transmitting acknowledgements by a TUE,according to embodiments of the present disclosure.

FIG. 9 is a flow chart illustrating an example method performed by abase station according to an embodiment of the present disclosure.

FIG. 10 is a flow chart illustrating an example method performed by acooperating UE (CUE) according to an embodiment of the presentdisclosure.

FIG. 11 is a flow chart illustrating an example method performed by atarget UE (TUE) according to an embodiment of the present disclosure.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

For illustrative purposes, specific example embodiments will now beexplained in greater detail below in conjunction with the figures.

The embodiments set forth herein represent information sufficient topractice the claimed subject matter and illustrate ways of practicingsuch subject matter. Upon reading the following description in light ofthe accompanying figures, those of skill in the art will understand theconcepts of the claimed subject matter and will recognize applicationsof these concepts not particularly addressed herein. It should beunderstood that these concepts and applications fall within the scope ofthe disclosure and the accompanying claims.

Moreover, it will be appreciated that any module, component, or devicedisclosed herein that executes instructions may include or otherwisehave access to a non-transitory computer/processor readable storagemedium or media for storage of information, such as computer/processorreadable instructions, data structures, program modules, and/or otherdata. A non-exhaustive list of examples of non-transitorycomputer/processor readable storage media includes magnetic cassettes,magnetic tape, magnetic disk storage or other magnetic storage devices,optical disks such as compact disc read-only memory (CD-ROM), digitalvideo discs or digital versatile discs (i.e. DVDs), Blu-ray Disc™, orother optical storage, volatile and non-volatile, removable andnon-removable media implemented in any method or technology,random-access memory (RAM), read-only memory (ROM), electricallyerasable programmable read-only memory (EEPROM), flash memory or othermemory technology. Any such non-transitory computer/processor storagemedia may be part of a device or accessible or connectable thereto.Computer/processor readable/executable instructions to implement anapplication or module described herein may be stored or otherwise heldby such non-transitory computer/processor readable storage media.

Many applications and services have reliability (and/or latency)requirements, e.g., ultra-reliable low latency communication (URLLC)services for high reliability will need to achieve a successful rate of99.9999% (and with latency of one or a few ms). UEs in a network can belocation anywhere, including the cell edge, but it can be almostimpossible for the cell-edge UEs to achieve URLLC high reliability,especially with limited transmission latency, e.g., 1 ms.

UE cooperation can enhance the system by potentially improving coverageand capacity. UE cooperation can also improve the latency andreliability of the system. The UE cooperation can be achieved by a groupof UEs helping each other with the Uu interface link transmission andsidelink (SL) transmission. The Uu interface link is the interface thatallows data transfer between the base station and a UE. Embodiments ofthe present disclosure aid in providing coordination and cooperationamong UE(s) in the group of UEs in terms of transmission and receptionby providing a manner for each transmitted/received message to beidentified based on a packet destination identifier and a packet sourceidentifier. The frequency band for transmission between a UE and basestation can be different from the frequency band for transmissionbetween users (SL). The frequency band for UL transmission between a UEand base station can be shared or separated from transmissions insidelink.

A UE in a configured UE group can identify whether it is the destinationor target UE or not based on a packet destination identifier. In someembodiments, this may occur without the UE having to decode the entirepacket. If the UE is the destination UE, the UE can then decode theentire packet. If the UE is not the destination UE, the UE can forwardthe packet to the destination UE or a UE in a path to the destination UEor simply other UE in the UE group. In some embodiments, once thedestination UE has received and decoded the packet, the destination UEcan send a hybrid automatic repeat request acknowledgement (HARQ-ACK)back to the source acknowledging the packet has been received. Thedestination UE may send the HARQ-ACK to the source directly, or throughone or more UEs in the group to the source.

FIGS. 1, 2A, 2B and 3 following below provide context for the networkand device that may be in the network and that may implement aspects ofthe present disclosure.

FIG. 1 illustrates an example communication system 100 in whichembodiments of the present disclosure could be implemented. In general,the system 100 enables multiple wireless or wired elements tocommunicate data and other content. The purpose of the system 100 may beto provide content (voice, data, video, text) via broadcast, narrowcast,user device to user device, etc. The system 100 may operate efficientlyby sharing resources such as bandwidth.

In this example, the communication system 100 includes electronicdevices (ED) 110 a-110 c, radio access networks (RANs) 120 a-120 b, acore network 130, a public switched telephone network (PSTN) 140, theInternet 150, and other networks 160. While certain numbers of thesecomponents or elements are shown in FIG. 1, any reasonable number ofthese components or elements may be included in the system 100.

The EDs 110 a-110 c are configured to operate, communicate, or both, inthe system 100. For example, the EDs 110 a-110 c are configured totransmit, receive, or both via wireless communication channels. Each ED110 a-110 c represents any suitable end user device for wirelessoperation and may include such devices (or may be referred to) as a userequipment/device (UE), wireless transmit/receive unit (WTRU), mobilestation, mobile subscriber unit, cellular telephone, station (STA),machine type communication device (MTC), personal digital assistant(PDA), smartphone, laptop, computer, touchpad, wireless sensor, orconsumer electronics device.

FIG. 1 illustrates an example communication system 100 in whichembodiments of the present disclosure could be implemented. In general,the communication system 100 enables multiple wireless or wired elementsto communicate data and other content. The purpose of the communicationsystem 100 may be to provide content (voice, data, video, text) viabroadcast, multicast, unicast, user device to user device, etc. Thecommunication system 100 may operate by sharing resources such asbandwidth.

In this example, the communication system 100 includes electronicdevices (ED) 110 a-110 c, radio access networks (RANs) 120 a-120 b, acore network 130, a public switched telephone network (PSTN) 140, theinternet 150, and other networks 160. Although certain numbers of thesecomponents or elements are shown in FIG. 1, any reasonable number ofthese components or elements may be included in the communication system100.

The EDs 110 a-110 c are configured to operate, communicate, or both, inthe communication system 100. For example, the EDs 110 a-110 c areconfigured to transmit, receive, or both via wireless or wiredcommunication channels. Each ED 110 a-110 c represents any suitable enduser device for wireless operation and may include such devices (or maybe referred to) as a user equipment/device (UE), wirelesstransmit/receive unit (WTRU), mobile station, fixed or mobile subscriberunit, cellular telephone, station (STA), machine type communication(MTC) device, personal digital assistant (PDA), smartphone, laptop,computer, tablet, wireless sensor, or consumer electronics device.

In FIG. 1, the RANs 120 a-120 b include base stations 170 a-170 b,respectively. Each base station 170 a-170 b is configured to wirelesslyinterface with one or more of the EDs 110 a-110 c to enable access toany other base station 170 a-170 b, the core network 130, the PSTN 140,the internet 150, and/or the other networks 160. For example, the basestations 170 a-170 b may include (or be) one or more of severalwell-known devices, such as a base transceiver station (BTS), a Node-B(NodeB), an evolved NodeB (eNodeB), a Home eNodeB, a gNodeB, atransmission and receive point (TRP), a site controller, an access point(AP), or a wireless router. Any ED 110 a-110 c may be alternatively oradditionally configured to interface, access, or communicate with anyother base station 170 a-170 b, the internet 150, the core network 130,the PSTN 140, the other networks 160, or any combination of thepreceding.

The EDs 110 a-110 c and base stations 170 a-170 b are examples ofcommunication equipment that can be configured to implement some or allof the functionality and/or embodiments described herein. In theembodiment shown in FIG. 1, the base station 170 a forms part of the RAN120 a, which may include other base stations, base station controller(s)(BSC), radio network controller(s) (RNC), relay nodes, elements, and/ordevices. Any base station 170 a, 170 b may be a single element, asshown, or multiple elements, distributed in the corresponding RAN, orotherwise. Also, the base station 170 b forms part of the RAN 120 b,which may include other base stations, elements, and/or devices. Eachbase station 170 a-170 b transmits and/or receives wireless signalswithin a particular geographic region or area, sometimes referred to asa “cell” or “coverage area”. A cell may be further divided into cellsectors, and a base station 170 a-170 b may, for example, employmultiple transceivers to provide service to multiple sectors. In someembodiments, there may be established pico or femto cells where theradio access technology supports such. In some embodiments, multipletransceivers could be used for each cell, for example usingmultiple-input multiple-output (MIMO) technology. The number of RAN 120a-120 b shown is exemplary only. Any number of RAN may be contemplatedwhen devising the communication system 100.

The base stations 170 a-170 b communicate with one or more of the EDs110 a-110 c over one or more air interfaces 190 using wirelesscommunication links e.g. radio frequency (RF), microwave, infrared (IR),etc. The air interfaces 190 may utilize any suitable radio accesstechnology. For example, the communication system 100 may implement oneor more orthogonal or non-orthogonal channel access methods, such ascode division multiple access (CDMA), time division multiple access(TDMA), frequency division multiple access (FDMA), orthogonal FDMA(OFDMA), or single-carrier FDMA (SC-FDMA) in the air interfaces 190.

A base station 170 a-170 b may implement Universal MobileTelecommunication System (UMTS) Terrestrial Radio Access (UTRA) toestablish an air interface 190 using wideband CDMA (WCDMA). In doing so,the base station 170 a-170 b may implement protocols such as High SpeedPacket Access (HSPA), Evolved HPSA (HSPA+) optionally including HighSpeed Downlink Packet Access (HSDPA), High Speed Packet Uplink Access(HSUPA) or both. Alternatively, a base station 170 a-170 b may establishan air interface 190 with Evolved UTMS Terrestrial Radio Access (E-UTRA)using LTE, LTE-A, and/or LTE-B. It is contemplated that thecommunication system 100 may use multiple channel access functionality,including such schemes as described above. Other radio technologies forimplementing air interfaces include IEEE 802.11, 802.15, 802.16,CDMA2000, CDMA2000 1×, CDMA2000 EV-DO, IS-2000, IS-95, IS-856, GSM,EDGE, and GERAN. Of course, other multiple access schemes and wirelessprotocols may be utilized.

The RANs 120 a-120 b are in communication with the core network 130 toprovide the EDs 110 a-110 c with various services such as voice, data,and other services. The RANs 120 a-120 b and/or the core network 130 maybe in direct or indirect communication with one or more other RANs (notshown), which may or may not be directly served by core network 130, andmay or may not employ the same radio access technology as RAN 120 a, RAN120 b or both. The core network 130 may also serve as a gateway accessbetween (i) the RANs 120 a-120 b or EDs 110 a-110 c or both, and (ii)other networks (such as the PSTN 140, the internet 150, and the othernetworks 160).

The EDs 110 a-110 c communicate with one another over one or more SL airinterfaces 180 using wireless communication links e.g. radio frequency(RF), microwave, infrared (IR), etc. The SL air interfaces 180 mayutilize any suitable radio access technology, and may be substantiallysimilar to the air interfaces 190 over which the EDs 110 a-110 ccommunication with one or more of the base stations 170 a-170 c, or theymay be substantially different. For example, the communication system100 may implement one or more channel access methods, such as codedivision multiple access (CDMA), time division multiple access (TDMA),frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), orsingle-carrier FDMA (SC-FDMA) in the SL air interfaces 180. In someembodiments, the SL air interfaces 180 may be, at least in part,implemented over unlicensed spectrum.

In this disclosure, the SL transmissions between cooperating UEs may be“grant-free” transmissions or as a mode for data transmissions that areperformed without communicating dynamic scheduling. Grant-freetransmissions are sometimes called “configured grant”, “grant-less”,“schedule free”, or “schedule-less” transmissions. Grant-free SLtransmissions can also be referred to as SL “transmission withoutgrant”, “transmission without dynamic grant”, “transmission withoutdynamic scheduling”, or “transmission using configured grant”, forexample.

A configured grant transmission typically requires the receiver to knowthe parameters and resources used by the transmitter for thetransmission. However, in the context of SL transmissions, the receivingUE is typically not aware of the transmitting UE's configurationparameters, such as which UE is transmitting, the ultimate target of thedata (e.g., another UE), the time-domain and frequency-domaincommunication resources used for the transmission, and other controlinformation. Various methods may be used to provide the configurationparameters and control information necessary for enabling configuredgrant transmissions in SL. The various methods will, however, each incura respective overhead penalty. Embodiments of the present disclosurecomprise including at least some of those configuration parametersand/or control information in the SL configured grant transmission,which may provide performance and/or overhead benefits.

In addition, some or all of the EDs 110 a-110 c may includefunctionality for communicating with different wireless networks overdifferent wireless links using different wireless technologies and/orprotocols. Instead of wireless communication (or in addition thereto),the EDs may communicate via wired communication channels to a serviceprovider or switch (not shown), and to the internet 150. PSTN 140 mayinclude circuit switched telephone networks for providing plain oldtelephone service (POTS). Internet 150 may include a network ofcomputers and subnets (intranets) or both, and incorporate protocols,such as internet protocol (IP), transmission control protocol (TCP) anduser datagram protocol (UDP). EDs 110 a-110 c may be multimode devicescapable of operation according to multiple radio access technologies,and incorporate multiple transceivers necessary to support multipleradio access technologies.

FIGS. 2A and 2B illustrate example devices that may implement themethods and teachings according to this disclosure. In particular, FIG.2A illustrates an example ED 110, and FIG. 2B illustrates an examplebase station 170. These components could be used in the system 100 or inany other suitable system.

As shown in FIG. 2A, the ED 110 includes at least one processing unit200. The processing unit 200 implements various processing operations ofthe ED 110. For example, the processing unit 200 could perform signalcoding, data processing, power control, input/output processing, or anyother functionality enabling the ED 110 to operate in the communicationsystem 100. The processing unit 200 may also be configured to implementsome or all of the functionality and/or embodiments described in moredetail herein. Each processing unit 200 includes any suitable processingor computing device configured to perform one or more operations. Eachprocessing unit 200 could, for example, include a microprocessor,microcontroller, digital signal processor, field programmable gatearray, or application specific integrated circuit.

The ED 110 also includes at least one transceiver 202. The transceiver202 is configured to modulate data or other content for transmission byat least one antenna or Network Interface Controller (NIC) 204. Thetransceiver 202 is also configured to demodulate data or other contentreceived by the at least one antenna 204. Each transceiver 202 includesany suitable structure for generating signals for wireless or wiredtransmission and/or processing signals received wirelessly or by wire.Each antenna 204 includes any suitable structure for transmitting and/orreceiving wireless or wired signals. One or multiple transceivers 202could be used in the ED 110. One or multiple antennas 204 could be usedin the ED 110. Although shown as a single functional unit, a transceiver202 could also be implemented using at least one transmitter and atleast one separate receiver.

The ED 110 further includes one or more input/output devices 206 orinterfaces (such as a wired interface to the internet 150). Theinput/output devices 206 permit interaction with a user or other devicesin the network. Each input/output device 206 includes any suitablestructure for providing information to or receiving information from auser, such as a speaker, microphone, keypad, keyboard, display, or touchscreen, including network interface communications.

In addition, the ED 110 includes at least one memory 208. The memory 208stores instructions and data used, generated, or collected by the ED110. For example, the memory 208 could store software instructions ormodules configured to implement some or all of the functionality and/orembodiments described above and that are executed by the processingunit(s) 200. Each memory 208 includes any suitable volatile and/ornon-volatile storage and retrieval device(s). Any suitable type ofmemory may be used, such as random access memory (RAM), read only memory(ROM), hard disk, optical disc, subscriber identity module (SIM) card,memory stick, secure digital (SD) memory card, and the like.

As shown in FIG. 2B, the base station 170 includes at least oneprocessing unit 250, at least one transmitter 252, at least one receiver254, one or more antennas 256, at least one memory 258, and one or moreinput/output devices or interfaces 266. A transceiver, not shown, may beused instead of the transmitter 252 and receiver 254. A scheduler 253may be coupled to the processing unit 250. The scheduler 253 may beincluded within or operated separately from the base station 170. Theprocessing unit 250 implements various processing operations of the basestation 170, such as signal coding, data processing, power control,input/output processing, or any other functionality. The processing unit250 can also be configured to implement some or all of the functionalityand/or embodiments described in more detail above. Each processing unit250 includes any suitable processing or computing device configured toperform one or more operations. Each processing unit 250 could, forexample, include a microprocessor, microcontroller, digital signalprocessor, field programmable gate array, or application specificintegrated circuit.

Each transmitter 252 includes any suitable structure for generatingsignals for wireless or wired transmission to one or more EDs or otherdevices. Each receiver 254 includes any suitable structure forprocessing signals received wirelessly or by wire from one or more EDsor other devices. Although shown as separate components, at least onetransmitter 252 and at least one receiver 254 could be combined into atransceiver. Each antenna 256 includes any suitable structure fortransmitting and/or receiving wireless or wired signals. Although acommon antenna 256 is shown here as being coupled to both thetransmitter 252 and the receiver 254, one or more antennas 256 could becoupled to the transmitter(s) 252, and one or more separate antennas 256could be coupled to the receiver(s) 254. Each memory 258 includes anysuitable volatile and/or non-volatile storage and retrieval device(s)such as those described above in connection to the ED 110. The memory258 stores instructions and data used, generated, or collected by thebase station 170. For example, the memory 258 could store softwareinstructions or modules configured to implement some or all of thefunctionality and/or embodiments described above and that are executedby the processing unit(s) 250.

Each input/output device 266 permits interaction with a user or otherdevices in the network. Each input/output device 266 includes anysuitable structure for providing information to or receiving/providinginformation from a user, including network interface communications.

Additional details regarding the UEs 110 and the base stations 170 areknown to those of skill in the art. As such, these details are omittedhere for clarity.

FIG. 3 is a block diagram illustrating an example of a network 352serving two UEs 354 a and 354 b, according to one embodiment. The twoUEs 354 a and 354 b may be, for example, the two UEs 110 a and 100 b inFIG. 1. However, more generally this need not be the case, which is whydifferent reference numerals are used in FIG. 3.

The network 352 includes a BS 356 and a managing module 358. Themanaging module 358 instructs the BS 356 to perform actions. Themanaging module 358 is illustrated as physically separate from the BS356 and coupled to the BS 356 via a communication link 360. For example,the managing module 358 may be part of a server in the network 352.Alternatively, the managing module 358 may be part of the BS 356.

The managing module 358 includes a processor 362, a memory 364, and acommunication module 366. The communication module 366 is implemented bythe processor 362 when the processor 362 accesses and executes a seriesof instructions stored in the memory 364, the instructions defining theactions of the communication module 366. When the instructions areexecuted, the communication module 366 causes the BS 356 to perform theactions described herein so that the network 352 can establish,coordinate, instruct, and/or control a UE group. Alternatively, thecommunication module 366 may be implemented using dedicated circuitry,such as an application specific integrated circuit (ASIC) or aprogrammed field programmable gate array (FPGA).

The UE 354 a includes a communication subsystem 370 a, two antennas 372a and 374 a, a processor 376 a, and a memory 378 a. The UE 354 a alsoincludes a communication module 380 a. The communication module 380 a isimplemented by the processor 376 a when the processor 376 a accesses andexecutes a series of instructions stored in the memory 378 a, theinstructions defining the actions of the communication module 380 a.When the instructions are executed, the communication module 380 acauses the UE 354 a to perform the actions described herein in relationto establishing and participating in a UE group. Alternatively, themodule 380 a may be implemented by dedicated circuitry, such as an ASICor an FPGA.

The communication subsystem 370 a includes processing andtransmit/receive circuitry for sending messages from and receivingmessages at the UE 354 a. Although one communication subsystem 370 a isillustrated, the communication subsystem 370 a may be multiplecommunication subsystems. Antenna 372 a transmits wireless communicationsignals to, and receives wireless communications signals from, the BS356. Antenna 374 a transmits SL communication signals to, and receivesSL communication signals from, other UEs, including UE 354 b. In someimplementations there may not be two separate antennas 372 a and 374 a.A single antenna may be used. Alternatively, there may be severalantennas, but not separated into antennas dedicated only to SLcommunication and antennas dedicated only to communicating with the BS356.

SL communications could be over W-Fi, in which case the antenna 374 amay be a Wi-Fi antenna. Alternatively, the SL communications could beover Bluetooth™, in which case the antenna 374 a may be a Bluetooth™antenna. SL communications could also or instead be over licensed orunlicensed spectrum.

The UE 354 b includes the same components described above with respectto the UE 354 a. That is, UE 354 b includes communication subsystem 370b, antennas 372 b and 374 b, processor 376 b, memory 378 b, andcommunication module 380 b.

The UE 354 a is designated as a target UE (TUE) and will therefore becalled TUE 354 a. The UE 354 b is a cooperating UE and will therefore becalled CUE 354 b. The CUE 354 b may be able to assist with wirelesscommunications between the BS 356 and TUE 354 a if a UE group were to beestablished that included TUE 354 a and CUE 354 b.

UE 354 a may be specifically chosen as the target UE by the network 352.Alternatively, the UE 354 a may itself determine that it wants to be atarget UE and inform the network 352 by sending a message to the BS 356.Example reasons why UE 354 a may choose or be selected by the network352 to be a target UE include: low wireless channel quality between theUE 354 a and the BS 356, many packets to be communicated between the BS356 and the UE 354 a, and/or the presence of a cooperating UE that is agood candidate for helping with communications between the BS 356 andthe UE 354 a.

UE 354 a need not always stay a target UE. For example, UE 354 a maylose its status as a target UE once there is no longer a need or desirefor assistance with wireless communications between UE 354 a and the BS356. UE 354 a may assist another target UE that is a cooperating UE at alater time. In general, a particular UE may sometimes be a target UE andother times may be a cooperating UE assisting another target UE. Also,sometimes a particular UE may be both a target UE receiving assistancefrom one or more cooperating UEs and also a cooperating UE itselfassisting another target UE. In the examples below, the UE 354 a actsonly as a target UE, i.e., TUE 354 a, and the UE 354 b is a cooperatingUE to the TUE 354 a, i.e., CUE 354 b.

FIG. 3 illustrates a system in which embodiments could be implemented.In some embodiments, a UE includes a processor, such as 376 a, 376 b inFIG. 3, and a non-transitory computer readable storage medium, such as378 a, 378 b in FIG. 3, storing programming for execution by theprocessor. A non-transitory computer readable storage medium could alsoor instead be provided separately, as a computer program product.

In such embodiments, programming could include instructions to: receive,by the UE, a packet comprising a UE group identifier and furthercomprising a packet destination identifier that identifies a destinationUE and determining, by the UE, if the UE is the destination UE. When theUE is the destination UE, the UE decoding the packet and when the UE isnot the destination UE, the UE forwarding the packet to another UE.

For UEs close to a cell edge or experiencing otherwise poor channelconditions, their performance can be enhanced via a help from other UEsthat have a relatively better channel conditions in terms of spectrumefficiency or transmission coverage.

Cooperative UEs (CUEs) in the network that have better transmissioncoverage can help target UEs (TUEs) for both downlink (DL) and uplink(UL) transmissions. DL and UL transmission here are intended to includetransmissions from the base station to the TUE and the TUE to the basestation, respectively, even if the path from one point to the otherincludes one or more CUE. One or more CUEs in the path are able toprovide natural spatial diversity and redundant signals to the TUE. TheTUE and nearby CUEs can form a helping group for UE cooperation. Theremay be only one TUE or multiple TUEs in a UE group.

FIG. 4 illustrates three different types of packet transmissions thatmay occur between a base station and a group of UEs that are predefinedas being in a same group. FIG. 4 includes a base station (gNB) 410 andseveral UEs (420 a, 420 b, 420 c, 420 d, 420 e and 420 f) that are partof UE group 430. The base station 410 can transmit and receive from UEs,for example as indicated by Uu downlink (DL) transmission 412 to UE 420a and by Uu uplink (UL) transmission 414 from UE 420 f. The UEs cantransmit and received amongst themselves as indicated by sidelink (SL)transmission 422 between UE 420 a and UE 420 b, by SL transmission 424between UE 420 c and UE 420 d and by SL transmission 426 between UE 420e and UE 420 f.

Type #1: The Transmission is Between a Base Station and a UE in aPredefined UE Group

The base station sends a packet in Uu DL by multicasting to a group ofUEs. The cyclic redundancy code (CRC) of the packet can be scrambled bya target UE (TUE) ID or a group UE ID that is used to identify UEs inthe predefined group of UEs. The TUE ID would typically by considered atype of global identifier of the UE that is the target destination ofthe packet. An example of this is a Radio Network Temporary Identifier(RNTI). The RNTI is a 16-bit long identifier that is assigned by thebase station regardless of whether the UE is performing UE cooperationor not. The RNTI can be used to scramble the CRC and decode informationbits of the packet for the TUE. The UEs in the group could receive thepacket and identify a destination for the packet, i.e. the destinationUE. If the packet is not for the UE, the UE can forward the packetthrough amplify and forward (AF) or decode and forward (DF) methods. Insome embodiments, the packet is forwarded using grant free (GF)transmission, also known as configured grant transmission. If a UEreceives and identifies the package is for itself, the UE can decode thepacket. The target UE (TUE) can identify a source of the packet and senda Hybrid-Automatic Repeat Request (HARQ) acknowledgement (ACK) to thesource, either directly or via one or more CUE.

Type #2: The Transmission is Between UEs within the UE Group

The UE(s) in the UE group can send a packet using SL to another UE. Insome embodiments this may include using a configured grant transmission.The CRC of the packet can be scrambled by a target UE (TUE) ID or thegroup UE ID. The UEs in the UE group can receive the packet and identifya destination for the packet. If the packet is not for the UE, the UEcan forward the packet through AF or DF methods. In some embodiments,the packet is forwarded using configured grant transmission. If the UEreceives and identifies the packet is for itself, the UE can decode thepacket. The TUE can identify a source of the packet and send a HARQ ACKto the source, either directly or via one or more CUE.

Type #3: The Transmission is from a UE in a Predefined UE Group to aBase Station

If the UE knows, or can determine, that the UE is within the coveragearea of Uu UL, the UE can send the packet directly to the base stationusing Uu UL. In some embodiments, the packet is transmitted usingconfigured grant transmission. If the UE in the UE group knows, or candetermine, that the UE is not within the coverage area of Uu UL, the UEsends the packet using SL to one or more UEs. In some embodiments, thepacket is transmitted using configured grant transmission. The CRC ofthe packet can be scrambled by the TUE ID, or the group UE ID. The UEsin the UE group can receive the packet and identify a destination forthe packet. If the packet is not for the UE, the UE in the UE group canforward the packet through AF or DF methods. In some embodiments, thepacket is forwarded using configured grant transmission. If the UEreceives and identifies the packet is for the base station, and the UEis within the coverage area of Uu UL, the UE can transmit the packetdirectly to the base station using Uu UL. In some embodiments, thepacket is transmitted using configured grant transmission.

The packets in these types of transmissions could carry one or acombination of data and control information from lower or higher layers.

To make the UE cooperation (UC) operational, UEs in vicinity will needto form a UE cooperation group and the UE cooperation will involve bothtransmissions between base station (Uu link) and UEs and sidelink (SL)transmissions.

In embodiments of this disclosure, UE cooperation involves the CUEsforwarding or relaying traffic to or from one or more TUEs. In someimplementations, this may include with redundant signal transmissions orreceptions. In order for redundant signal transmissions to be combinedor detected more efficiently, redundant signals transmitted or receivedby each UE (CUE or TUE) have to be configured such that the redundantversion signals are transmitted or received in a cooperative way.Redundant version signals from each CUE (or TUE) and from differenttransmission time intervals must be clearly defined or indicated, forexample, by SL control signaling or SL control information, SCI, in aformat such as SCI format 0-1 or SCI format 0-2 in 5G/NR specifications.In the case of downlink from base station to a target UE, even if oneCUE from a group of helping UEs is not able to forward the traffic dueto not being able to successfully detect traffic towards the TUE(s), theredundant version signals from other UEs can still be efficiently andjointly detected at the TUE(s), where, for example, a redundant versionfor initial transmission and a redundant transmission for each CUE maybe used such that the initial transmission with the redundant versioncan be self-decodable and a redundant version for each transmission canbe pre-configured or dynamically indicated by SL SCI in a format such asSCI 0-2. The redundant version signals from one or more UEs can berepeated if a NACK is received from the reception end. When thecapability of multiple repetitions of a packet transmission from one ormore UEs is configured, the repetition transmissions of the packet canbe terminated timely by an ACK from the reception end, for example, toavoid unnecessary interference to the system.

Towards this end, configuration and signaling mechanisms are describedherein to make the UE cooperation perform smoothly and effectively. Inthe Uu link, the base station will need to configure UEs in a UE group,which may include one or more of: a configuration of the transmissionand receiving resources, configuration of redundant signal versions(such as chase combining or incremental redundancy), configuration of atransmission diversity scheme (such as a cyclic delay diversity orAlamouti encoding), configuration of a forwarding scheme (such as decodeand forward) for a UE in the UC group, and an indication of whether touse unicast, group-cast or broadcast in transmissions of a TUE (TUEs)packet upon its arrival to the UC group from a base station.

In UC SL for a downlink transmission, one or more CUEs receive/detect apacket transmitted on a Uu link, the CUE or CUEs who correctly receivethe packet and have been configured as helping UEs will forward/sendinformation in the packet to the associated TUE(s). Each CUE isconfigured with redundant version signals of the packet. The configuringmay be pre-configuration, semi-statically configuring, or dynamicallyconfiguring such as SCI signaling in each SL transmission. The CUEsforward redundant signal versions of the packet in dedicated resourcesor shared resources with same or different HARQ IDs to a TUE. In oneembodiment, the CUEs forward redundant version signals/transmissions ofthe packet, each in CUE dedicated resources, with a single HARQ ID(associated with the packet), for all CUE transmissions to the TUE,where one or more of: the redundant version signal information, the HARQID, diversity scheme, forwarding scheme, TUE ID/designation ID in the UCgroup and MCS may be indicated (or dynamically configured) by SCItogether with each transmission. In another embodiment, the CUEs forwardredundant version signals/transmissions of the packet, each in CUEdedicated resources, with a different HARQ ID, to the TUE where thesedifferent HARQ IDs from different CUE transmissions are associated withthe packet, and one or more of: the redundant version signalinformation, an HARQ ID, diversity scheme, forwarding scheme, TUEID/designation ID in the UC group and MCS may be indicated (ordynamically configured) by SCI together with each transmission from aCUE. The resource may be configured by pre-configuration,semi-statically configuring, or dynamically configuring (or indicating).The CUEs that are not able to correctly detect a packet in atransmission time interval (TTI) will not forward anything.

A redundant signal version can use chase combining (CC) or incrementalredundancy (IR). A transmission diversity scheme can be a cyclic delaydiversity (CDD) version or an Alamouti encoding. A forwarding scheme canbe any one of amplify and forward (AF), decode and forward (DF),compress and forward (CF), quantization and forward (QF), etc. Thesetransmission parameters including the redundant version, diversity andforwarding schemes can be pre-configured, semi-statically configure ordynamically configured, for example in some embodiments using sidelinkcontrol information (SCI) signaling for example, in a way of SCI 0-1or/and SCI 0-2 format.

Meanwhile, the one or more TUEs can receive and detect the signaldirectly received over the Uu link (if possible), as well as theredundant version signals from CUE(s). Once detected, the TUE(S) mayprovide feedback to CUE(s) or a base station accordingly based on afeedback channel or time-frequency resource configuration from a basestation or a designated UE such as CUE.

In UC SL for an upward (from a TUE to base station or network)transmission, one (or more TUEs) can forward its (or their) packet(s) toone or more CUEs, and the CUE(s) will then forward upward to the basestation.

FIGS. 5A, 5B, 5C, and 5D provide additional examples of UE cooperationin which various combinations of unicast and multicast transmissionsoccur between a base station, one or more cooperating UEs and one ormore target UEs.

Each of the four examples includes a base station (gNB) transmitting toand receiving from up to four cooperating UEs (CUE₁, CUE₂, CUE₃, andCUE₄) on a Uu link. The up to four cooperating UEs (CUE₁, CUE₂, CUE₃,and CUE₅₄) are transmitting to and receiving from up to two target UEson a sidelink (SL) link (TUE₅, TUE₆).

In FIG. 5A, as part of a configuration process, the base station (gNB)510 notifies CUE₂ that CUE₂ is to aid forwarding packets to TUE₅ andCUE₃ is notified that it is to aid forwarding packets to TUE₆. Then whenthe gNB 510 forwards packets by unicast intended for TUE₅ on the Uulink, CUE₂ receives the packets and forwards them to TUE₅ on the SL andwhen the gNB 510 forwards packets by unicast intended for TUE₆ on the Uulink, CUE₃ receives the packets and forwards them to TUE₆ on the SL. Insome embodiments, TUE₅ or TUE₆ can also receive the signals directlyfrom the gNB 510 transmitting the packets. In such a situation, the TUEcan then combine received signals directly from the gNB 510 with signalsreceived from one of the CUEs. As CUE₂ and CUE₃ are each only configuredto aid a single TUE in this example, the SL transmissions use unicast totransmit to each TUE, respectively. The CUE-TUE relationship is fixedfor at least a given time period by configuration or until otherwisechanged by a new configuration by the gNB 510. In some embodiments, CUE₂and CUE₃ are each preconfigured to transmit using one or morerepetitions, each with redundant versions. Each initial transmission orrepetition has an associated HARQ ID to allow the receiving UE toidentify the particular transmission amongst other transmissions. Theconfiguration on the number of repetitions, redundant versions and HARQID can be pre-configured, semi-statically configured or dynamicallyconfigured, as will be described in further detail below. SLtransmission occasions (TOs) can be configured as configured grant (CG)transmissions or dynamically indicated, e.g., using sidelink controlinformation (SCI).

In FIG. 5B, as part of a configuration process, the gNB 510 notifiesCUE₂ that CUE₂ is to aid forwarding packets to TUE₅ and TUE₆. Then whenthe gNB 510 forwards packets by unicast intended for TUE₅ or TUE₆ on theUu link, CUE₂ receives the packets and forwards them to TUE₅ and TUE₆ onthe SL link. TUE₅ and TUE₆ will both decode the received signals andonly the TUE that the packets are targeted for will correctly detect thepackets. In some embodiments, TUE₅ or TUE₆ will also receive the signalsdirectly from the gNB 510 transmitting the packets. In such a situation,the TUE can then combine received signals directly from the gNB 510 withsignals received from one of the CUEs. As CUE₂ is configured to aid bothTUE₅ and TUE₆ in this example, the SL transmissions may be multi-cast orgroup-cast to transmit to both TUE₅ and TUE₆. The CUE-TUE relationshipis fixed for at least a given time period by configuration or untilotherwise changed by a new configuration by the gNB 510. In someembodiments, CUE₂ is preconfigured to transmit using one or morerepetitions, each with redundant versions. Each transmission has anassociated HARQ ID. The configuration on the number of repetitions,redundant versions and HARQ ID can be pre-configured, semi-staticallyconfigured or dynamically configured, as will be described in furtherdetail below. SL group-cast TOs can be configured as configured grant(CG) transmissions or dynamically indicated, e.g., using SCI.

In FIG. 5C, as part of a configuration process, the gNB 510 notifiesCUE₁ that CUE₁ is to aid forwarding packets to TUE₅, gNB 510 notifiesCUE₂ that CUE₂ is to aid forwarding packets to TUE₅, gNB 510 notifiesCUE₃ that CUE₃ is to aid forwarding packets to TUE₅ and TUE₆, and gNB510 notifies CUE₄ that CUE₄ is to aid forwarding packets to TUE₆. Thenwhen the gNB 510 forwards packets by group-cast or broadcast intendedfor TUE₅ or TUE₆ on the Uu link, CUE₁, CUE₂, CUE₃ and CUE₄ receive thepackets and whichever of the CUEs is able to correctly decode thepackets forwards the packets to TUE₅ or TUE₆ on the SL link. As CUE₁,CUE₂ and CUE₄ are each only configured to aid a single TUE in thisexample, the SL transmissions use unicast to transmit to the TUEs theyare respectively configured to aid. As CUE₃ is configured to aid bothTUE₅ and TUE₆ in this example, the SL transmissions may be multi-cast orgroup-cast to transmit to both TUE₅ and TUE₆; alternatively, it ispossible here for CUE₃ to use unicast transmission to TUE₅ and TUE₆,respectively. The packets received at the TUEs from the CUEs can be froma single CUE or combined from multiple CUEs as appropriate. The CUE-TUErelationship is fixed for at least a given time period by configurationor until otherwise changed by a new configuration by the gNB. In someembodiments, the CUEs are preconfigured to transmit using one or morerepetitions, each with redundant versions. Each transmission has anassociated HARQ ID. The configuration on the number of repetitions,redundant versions and HARQ ID can be pre-configured, semi-staticallyconfigured or dynamically configured, as will be described in furtherdetail below. A redundant signal version can utilize chase combining(CC) HARQ or incremental redundancy (IR) HARQ. The redundant signalversion may not utilize a transmission diversity scheme for a scenarioof one CUE to one TUE helping relationship or may utilize a transmissiondiversity scheme for a scenario of more than one CUE to one or more TUEshelping relationship, with CUEs forwarding in orthogonal time orfrequency resources. The redundant signal version may utilize a cyclicdelay diversity (CDD) or an Alamouti encoding for a scenario of morethan one CUE to one or more TUEs helping relationship with CUEssimultaneously forwarding in the same time-frequency resources. Thepacket transmission is also associated with a forwarding scheme (e.g.,amplify and forward (AF), decode and forward (DF), compress and forward(CF), etc.). The above configuration on these parameters can bepre-configured, semi-statically or dynamically configured (e.g., SCI).SL transmission occasions (TOs) can be pre-configured or semi-staticallyas CG transmissions or dynamically indicated, e.g., using SCI formultiple CUEs to transmit. In some embodiments, TUE₅ or TUE₆ can alsoreceive the signals directly from the gNB 510 transmitting the packets.In such a situation, the TUE can then combine received signals directlyfrom the gNB 510 with signals received from one of the CUEs asappropriate.

In FIG. 5D, as part of a configuration process, the gNB 510 notifiesCUE₂ that CUE₂ is to aid forwarding packets to TUE₅ and TUE₆ and gNB 510notifies CUE₃ that CUE₃ is to aid forwarding packets to TUE₅ and TUE₆.Then when the gNB 510 forwards packets by group-cast or broadcastintended for TUE₅ or TUE₆ on the Uu link CUE₂ and CUE₃ receive thepackets and forward them to TUE₅ or TUE₆ on the SL link. As CUE₂ andCUE₃ are configured to aid both TUE₅ and TUE₆ in this example, the SLtransmissions may be multi-cast or group-cast to transmit to both TUE₅and TUE₆. In this example CUE₁ and CUE₄ are not configured to help inforwarding packets to any particular TUE. Therefore, CUE₁ and CUE₄ donot forward the packets, even though they are received due to themulti-cast by the gNB 510. The packets received at the TUEs from theCUEs can be from a single CUE or combined from multiple CUEs asappropriate. The CUE-TUE relationship is fixed for at least a given timeperiod or until otherwise changed by a new configuration by the gNB 510.In some embodiments, the CUEs are preconfigured to transmit using one ormore repetitions, each with redundant versions. Each transmission has anassociated HARQ ID. The configuration on the number of repetitions,redundant versions and HARQ ID can be pre-configured, semi-staticallyconfigured or dynamically configured, as will be described in furtherdetail below. A redundant signal version can utilize CC HARQ or IR HARQ.The redundant signal version may not utilize a transmission diversityscheme for a scenario of one CUE to one TUE helping relationship or mayutilize a transmission diversity scheme for a scenario of more than oneCUE to one or more TUEs helping relationship, with CUEs forwarding inorthogonal time or frequency resources. The redundant signal version mayutilize a cyclic delay diversity (CDD) or an Alamouti encoding for ascenario of more than one CUE to one or more TUEs helping relationshipwith CUEs simultaneously forwarding in the same time-frequencyresources. The packet transmission is also associated with a forwardingscheme (e.g., AF, DF, CF, etc.). SL TOs can be pre-configured orsemi-statically as configured grant (CG) transmissions or dynamicallyindicated, e.g., using SCI for multiple CUEs to transmit. In someembodiments, TUE₅ or TUE₆ can also receive the signals directly from thegNB 510 transmitting the packets. In such a situation, the TUE can thencombine received signals directly from the gNB 510 with signals receivedfrom one of the CUEs.

In some embodiments for FIG. 5A, 5B, 5C or 5D, the gNB can forward onepacket by unicast, group-cast or broadcast intended for TUE₅ and TUE₆.FIGS. 5A, 5B, 5C and 5D each have only four UEs as CUEs and two UEs asTUEs, but it is to be understood that these are intended to benon-limiting examples. The number of UEs in a UE group, the number ofCUEs in the UE group and the number of TUEs in the UE group, which UEsin the UE group are designated to help particular TUEs, etc., are allimplementation specific variables.

FIG. 6 illustrates an example of signaling that may occur between a basestation and multiple UEs that have been identified as a cooperationgroup by the base station. Some of the multiple UEs are identified asTUEs and other of the multiple UEs are identified as CUEs, of which oneor more may be configured to aid in transmitting a packet to whichtarget UEs and to share some information of the target UEs such as atarget UE ID and/or its scrambling ID. The vertical axis is a temporalaxis and generally notes a passage of time. However, it is not intendedthat the signal messaging necessarily occurs in the exact order shown.Configuration to particular UEs may occur sequentially orsimultaneously. Signaling that may occur between the base station andone or multiple UEs in FIG. 6 includes UE resource configuration (orgroup-based resource allocation), UE cooperation (UC) groupinginformation (such as group ID, optionally a sub-group ID for one UE inthe group, etc.), and associated parameters including, for example,redundant signal versions. The base station performs a UE-specificconfiguration including the UE UC grouping information.

At a first instance 610, the base station sends configurationinformation to one or more cooperating UEs that includes one or more of:information to notify one or more CUEs which one or more TUEs to aid inforwarding packets intended for the one or more TUEs; information toidentify sidelink (SL) transmission and receiving resources that can beused for the group of UEs; information to identify redundant signals andrepetitions, e.g., {Ri1, Ri2} with Rep=2; information to identify adiversity scheme (e.g., CDD, Alamouti) if applicable (e.g., one CUE toone TUE helping relationship would not necessarily need a diversityscheme identification); and information to identify a forwarding scheme(e.g., amplify and forward, decode and forward, compress and forward).The configuration information can be sent via radio resource control(RRC) messaging or downlink control information (DCI) or sidelinkcontrol information (SCI), or some combination thereof. Theconfiguration information can be pre-configured, semi-staticallyconfigured or dynamically configured.

At a second instance 620, the base station sends configurationinformation to one or more target UEs that includes one or more of:information to identify sidelink (SL) transmission and receivingresources that can be used for the TUE(s), information to identify adiversity scheme (e.g, CDD, Alamouti), if applicable (e.g., one CUE toone TUE helping relationship would not necessarily need a diversityscheme identification); and optionally, information to identify aforwarding scheme (e.g., amplify and forward, decode and forward,compress and forward). The configuration information can be sent viaradio resource control (RRC) messaging or downlink control information(DCI) or sidelink control information (SCI), or some combinationthereof. The configuration information can be pre-configured,semi-statically configured or dynamically configured.

Configuration of additional UEs can occur in the same way.

In some embodiments, the common parameters being sent to a UC groupingcan be configured in a group-cast or broadcast signaling message,separate from UE specific configuration signaling messages. When thebase station is ready to send packets at another instance 630, the basestation can transmit packets via unicast or broadcast/group-castsignaling, as described in the example of FIGS. 5A, 5B, 5C and 5D above,with a destination or TUE identifier (ID) indicated in the transmission.The TUE ID may be included in a DCI or uplink control information (UCI)multiplexed with data; alternatively, the TUE ID may be included in MACCE or even in a higher layer entity such as packet data convergenceprotocol (PDCP), Radio Link Control (RLC), or/and Internet Protocol (IP)layer. Usually, different types of relay devices may carry a designationID in different protocol entities; for example, Layer 2 (L2) relay mayinclude a target UE ID or destination ID in a PDCP/RLC layer while Layer3 (L3) relay may include a target UE ID or destination ID in an IPlayer. For a UC group where one or more CUEs are to help forward thereceived traffic intended for (or from) a TUE, each of the CUEs may getor know from the received traffic the TUE ID, the destination ID of thetraffic, or/and the sub-group ID (for the TUE) within the UC group,etc., via Layer 1 (L1) signaling (such as DCI or SCI), MAC CE associatedwith the traffic, or/and in a higher layer entity (within the traffic)such as PDCP, RLC, or/and IP layer, in order for the SL transmission. Inone embodiment, a TUE may provide, for example, during initial UC groupsetup or by a request for help from a UC group, an identification of theTUE (the TUE ID, or the packet destination ID in the UC group) to one ormore CUEs in the UC group, allowing the one or more CUEs for forwardingany packets intended for the TUE. In other embodiments, if more than oneCUE in a UC group, any TUE in the UC group may have at least oneassociated CUE configured to forward the packets intended for the TUE,which is activated by default; and the TUE in the UC group may have theother CUE(s) to help the TUE only on a demand basis, which may requireadditional signaling(s) to indicate or activate the forwardingfunctionality to the TUE.

FIGS. 7A, 7B and 7C provide examples of how a CUE may transmit andreceive transmissions with one or more TUE. Although FIGS. 7A, 7B and 7Ceach show a CUE communicating with two TUEs, it is to be understood thatother implementations may include the CUE communicating a single TUE ormore than two TUEs. In addition, other implementations may involve afirst CUE forwarding to a second CUE that is closer to a TUE than thefirst CUE, and then the second CUE forwarding to the TUE. In FIGS. 7A,7B and 7C the vertical axis is a temporal axis and generally notes apassage of time. However, it is not intended that the signal messagingnecessarily occurs in the exact order shown. Signaling to particular UEsmay occur sequentially or simultaneously.

FIG. 7A illustrates an example of UE cooperative (UC) sidelink (SL)configured Grant (CG) transmissions of a TUE packet with redundantversion signals without applying any dynamic indication or controlmessage.

In the example of FIG. 7A, a CUE, identified as CUE_(i) (where iindicated one of a configured group of UEs) has detected a packetintended for one or more TUEs, for example TUE_(k) or TUE_(j). At afirst instance 710, CUE_(i) performs a transmission in a configuredgrant transmission resource (that may have been configured as describedabove with reference to FIG. 6) and with a configured redundant signalversion (R_(i)1) having a particular modulation and coding scheme (MCS)for a 1^(st) data transmission. The transmission may be transmitted viaunicast, broadcast or group-cast depending on the CUE-TUE configurationrelationship types as described in FIG. 5A, 5B, 5C or 5D. The particularformat or transmission mode (e.g., group-cast) can be predefined,pre-configured or configured by configured grant transmission. A HARQ IDof the transmission can be determined implicitly by the TUE based on theconfigured transmission resources used for the transmission (e.g., timeor/and frequency domain resources). For a first redundant transmissionof the packet 712, CUE_(i) will perform transmission in the configuredgrant transmission resource and with configured redundant signal version(R_(i)2) and with a particular MCS for the 2nd data transmission. Thetransmission can be transmitted via unicast, broadcast or group-cast,which can be predefined, pre-configured or GF configured. The sameprocess can be repeated for third or fourth redundant transmissions, ifconfigured, and so forth.

Meanwhile, any other CUE that has been notified that it should aid inthe transmission of packets to TUE_(k) and/or TUE_(j) and that hassuccessfully detected a packet can also forward the TUEs data withconfigured grant transmissions, if configured, in appropriatelyconfigured time-frequency resources, which may be the same as, ordifferent from, CUE_(i).

The feedback from TUE_(k) and from TUE_(j) to one or more CUEs, shown atinstances 714 and 716, respectively, can be transmitted in configuredgrant feedback channels or other data transmission resources. Moreover,the feedback from TUE_(k) and from TUE_(j) to one or more CUEs can beoptional. For example, in some cases of low latency applications, suchas URLLC services, a particular number of repetitions may take a periodof a few TTIs, which is close to the limit of the latency requirementwindow for the low latency applications. The feedback may not bemeaningful, regardless of whether the transmission successful or not, asthe network is done with the transmitted time-sensitive packet due tothe latency limitations.

FIG. 7B illustrates an example of UC SL CG transmissions with sidelinkcontrol information (SCI) or uplink control information (UCI) fortransmission of a TUE packet (with redundant version signals).

In the example of FIG. 7B, a CUE, identified again as CUE_(i) hasdetected a packet intended for one or more TUEs, for example TUE_(k) orTUE_(j). At a first instance 720, CUE_(i) performs a transmission in aconfigured grant transmission resource (that may have been configured asdescribed above with reference to FIG. 6) with SCI that includes one ormore of: an identification of redundant signal version (R_(i)1), aparticular MCS, a HARQ ID for a 1st data transmission, diversity scheme,forwarding scheme, feedback related info and resourceallocation/indication, CUE/source ID and TUE ID/designation ID in the UCgroup. The transmission in the SL may be transmitted via unicast,broadcast or group-cast and the transmission type can be predefined,pre-configured or configured by configured grant transmission. For afirst redundant transmission of the packet 722, CUE_(i) will performtransmission in the configured grant transmission resource with SCI thatincludes one or more of: an identification of redundant signal version(R_(i)2), a particular MCS and a HARQ ID for a 2nd data transmission,diversity scheme, forwarding scheme, feedback related info and resourceallocation/indication, CUE/source ID and TUE ID/designation ID in the UCgroup. Optionally, the SCI may also include an indication as to whichdiversity/forwarding scheme or which one among more than onediversity/forwarding scheme to use in either an initial or/and aredundant transmission. The transmission can be transmitted via unicast,broadcast or group-cast, which can be predefined, pre-configured or GFconfigured. The same process can be repeated for third or fourthredundant transmissions, if configured, and so forth.

Meanwhile, any other CUE that has been notified that it should aid inthe transmission of packets to TUE_(k) and/or TUE_(j) and that hassuccessfully detected a packet can also forward the TUEs data withconfigured grant transmissions, if configured, in appropriatelyconfigured time-frequency resources, which may be the same as, ordifferent from, CUE_(i).

The feedback from TUE_(k) and from TUE_(j) to one or more CUEs, shown atinstances 724 and 726, respectively, can be transmitted in configuredgrant feedback channels or SCI dynamically indicated feedback channelsor data transmission resources. Moreover, the feedback from TUE_(k) andfrom TUE_(j) to one or more CUEs can be optional. For example, in somecases of low latency applications, such as URLLC services, a particularnumber of repetitions may take a period of a few TTIs, which is close tothe limit of the latency requirement window for the low latencyapplications. The feedback may not be meaningful, regardless of whetherthe transmission successful or not, as the network is done with thetransmitted time-sensitive packet due to the latency limitations.

FIG. 7C illustrates an example of UC SL GB transmissions with SCI or UCIfor transmission of a TUE packet with redundant version signals byapplying a dynamic indication or control message.

In the example of FIG. 7C, a CUE, identified again as CUE has detected apacket intended for one or more TUE, for example TUE_(k) or TUE_(j). Ata first instance 730, CUE_(i) performs a transmission on a dynamicallyconfigured transmission resource by SCI which also includes anidentification of redundant signal version (R_(i)1), a particular MCSand a HARQ ID for a 1^(st) data transmission. The transmission in the SLmay be transmitted via unicast, broadcast or group-cast, and thetransmission type can be predefined, pre-configured or configured byconfigured grant transmission. For a first redundant transmission of thepacket 732, CUE_(i) will perform transmission in a dynamicallyconfigured transmission resource by SCI that also includes anidentification of redundant signal version (R_(i)2), a particular MCSand a HARQ ID for a 2nd data transmission. Optionally, the SCI may alsoinclude an indication as to which diversity/forwarding scheme or whichone among more than one diversity/forwarding scheme to use in an initialor/and a redundant transmission. The transmission can be transmitted viaunicast, broadcast or group-cast, which can be predefined,pre-configured or GF configured. The same process can be repeated forthird or fourth redundant transmissions, if configured, and so forth.

Meanwhile, any other CUE that has been notified that it should aid inthe transmission of packets to TUE_(k) and/or TUE_(j) and that hassuccessfully detected a packet can also forward the TUEs data with grantbased transmissions, if configured, in dynamically SCI configuredtransmission resources, which may be the same as, or different from,CUE_(i) along with the SCI indicated other transmission parameters.

The feedback from TUE_(k) and from TUE_(j) to one or more CUEs, shown atinstances 734 and 736, respectively, can be transmitted inpre-configured or SCI dynamically indicated feedback channels or datatransmission resources. Moreover, the feedback from TUE_(k) and fromTUE_(j) to one or more CUEs can be optional. For example, in some casesof low latency applications, such as URLLC services, a particular numberof repetitions may take a period of a few TTIs, which is close to thelimit of the latency requirement window for the low latencyapplications. The feedback may not be meaningful, regardless of whetherthe transmission successful or not, as the network is done with thetransmitted time-sensitive packet due to the latency limitations.

FIG. 8 is a schematic diagram showing examples of transmission ofpackets over a Uu link from a base station to multiple CUEs and thenseveral of the CUEs forwarding the packets onto multiple TUEs. Thehorizontal axis is representative of increasing time.

Multiple packets 810 are shown being transmitted on the Uu link. Inparticular 810 a and 810 b are two packets being transmitted to TUE₅ inrespective transmission opportunities (TOs). The packets are group-castor broadcast in the Uu link so as to enable any CUEs that can receivethe packets and if having correctly decoded one or more of the packets,to forward to TUE₅, where DF forwarding scheme is assumed. In anotherembodiment, the packets are unicast in the Uu link to individual CUEs(respectively) in dedicated or shared resources that can receive thepackets and if having correctly decoded one or more of the packets, toforward to TUE₅, where DF forwarding scheme is assumed. In someembodiments, the designated CUEs (i.e., CUE₁, CUE₂, and CUE₃ in thiscase) will utilize the AF scheme to forward the received packets to TUE₅in respective transmission opportunities (TOs).

CUE₁ receives the first packet (Pkt 1) and forwards a first redundantsignal version (R_(1,1)) of the packet in a first sidelink (SL)transmission opportunity (TO) 820. CUE₂ is not shown forwarding thepacket; this may be because CUE₂ do not receive Pkt 1, or did notreceive a version of Pkt 1 worth transmitting. CUE₃ receives Pkt 1 andforwards a first redundant signal version (R_(3,1)) of the packet in thefirst SL TO 820. Arrows pointing from CUE₁ and CUE₃ to SL TO 820 andfrom SL TO 820 to the TUE₅ and TUE₆ are simply for clarity to show whenthe CUEs are transmitting and then that the contents of SL TO 820 arebroadcast to which respective TUEs.

TO 822 is configured resource used for an acknowledgment (ACK) or anegative acknowledgement (NACK) to be (optionally) sent from TUE₅ (orTUE₆ not shown in the figure) to any of the CUEs (or to receive by anyof the CUEs). In this particular instance TUE₅ does not send an ACK orNACK. Since CUE₁ and CUE₃ do not receive an ACK or NACK, they send arepetition of Pkt 1 in next configured resource (i.e., TO 824 in thiscase). CUE₁ forwards a second redundant signal version (R_(1,2)) of thepacket (Pkt 1) in a second SL TO 824. CUE₂ once again does not forwardthe packet. CUE₃ forwards a second redundant signal version (R_(3,2)) ofthe packet in the second SL TO 824. Arrows pointing from CUE₁ and CUE₃to SL TO 820 and from SL TO 820 to the TUE₅ and TUE₆ are simply forclarity to show when the CUEs are transmitting and then that thecontents of SL TO 820 are broadcast to which respective TUEs. In someembodiments, TOs 820 and 824 each can be shared resource among differentCUEs or can be split (e.g., time, frequency, spatial, etc.) resourcesfor the data/control info transmissions among the CUEs; and TO 822 canbe shared resource among different TUEs or can be split (e.g., time,frequency, spatial, etc.) resources for the data/control infotransmissions among the TUEs; and the above statements are alsoapplicable to other SL TOs (such as TOs 826, 828, etc.) in FIG. 8.

TO 826 is for an ACK or a NACK to be (optionally) sent from TUE₅ (orTUE₆) to any of the CUEs. In this particular instance TUE₅ does send anACK as a result of the maximum number of the configured transmissions(i.e., 2) for the Pkt 1 having been achieved. Optionally, one or more ofthe CUEs can then forward the ACK to the base station (not shown).

With respect to a second Packet (Pkt 2), CUE₁ is receives it andforwards a first redundant signal version (R_(1,1)) of the packet in afirst SL TO 830. CUE₂ receives Pkt 2 (e.g., correctly) and forwards afirst redundant signal version (R_(2,1)) of Pkt 2 in the first SL TO830. CUE₃ receives Pkt 2 and forwards a first redundant signal version(R_(3,1)) of the packet in the first SL TO 830.

TO 832 is for an ACK or a NACK to be (optionally) sent from TUE₅ to anyof the CUEs. In this particular instance TUE₅ (as correctly decoding thePkt 2) does send an ACK to avoid the CUEs to send more repetitions ofPkt 2, thus reducing the intra-cell and inter-cell interference in thenetwork.

Redundant signal version and repetition configuration for each CUE canbe pre-configured, semi-statically configured or dynamically configured,as described above.

FIG. 9 is an example flow diagram 900 that describes a method how UEcooperation can be performed in accordance with an aspect of thisdisclosure. The flow diagram 900 involves a base station configuring oneor more CUEs and one or more TUEs as one UC group, and then transmittingpackets upon traffic arrivals over the Uu link. Prior to theconfiguration of the CUEs and TUEs the base station may have determinedan appropriate UE group that contains the CUEs and TUEs, and thenprovided through configuration (with higher-layer and/or L1 signaling)the UEs in the group with UE cooperation (UC) group pertinent UCgrouping information such as which CUE(s) to help which TUE(s) and someshared information on each TUE, e.g., UE ID, subgroup ID in the UCgroup, and/or UE scrambling ID, etc., by the configured helping CUE(s).The base station may configure and transmit the UC grouping informationto the UEs together with a configuration procedure of other operationmodes (such as V2X, normal NR), e.g., UE resource and parameterconfiguration information. Or, the base station may configure UC modeseparately (or independently) from that of the other operation modes.

At 910, at least one base station transmits configuration information toat least one CUE. The configuration information includes at least:sidelink (SL) transmission resources available to be used by the atleast one CUE forwarding packets intended for the TUE (or TUEs) and aredundancy parameter for SL transmissions. At 915, the configurationinformation may also optionally include: an identification of a TUE (ormore TUEs) that the at least one CUE is to aid by forwarding packetsintended for the TUE (or TUEs); sidelink (SL) transmission resourcesavailable to be used by the at least one CUE for receivingacknowledgments from the TUE (or TUEs); an identification of redundanttransmission signals associated with a specific CUE and a number ofrepetitions; a diversity scheme to be used for transmission by the atleast one CUE; and a forwarding scheme to be used for transmission bythe at least one CUE. Additionally, or alternatively, the TUE mayprovide an identification of the TUE to at least one CUE during initialUE cooperation setup or during a request procedure that the TUE asks forhelp from the CUE.

At 920, the at least one base station transmits configurationinformation to the TUE. The configuration information includes at least:SL transmission resources available to be used by the TUE for receivingpackets transmitted from the at least one CUE and a redundancy parameterfor SL transmissions. At 925, the at least one base station optionallytransmits configuration including SL transmission resources available tobe used by the TUE for transmitting acknowledgments to the at least oneCUE; an identification of initial or redundant transmission signalsassociated with the TUE and a number of repetitions; and a diversityscheme to be used for transmission by the TUE.

At 930, the at least one base station transmits a packet that isintended for the TUE via unicast, groupcast, multicast or broadcast tothe plurality of UEs.

FIG. 10 is an example flow diagram 1000 that describes a method how UEcooperation can be performed in accordance with an aspect of thisdisclosure. The flow diagram 1000 involves a UE that is a CUE receivingconfiguration information from a base station, receiving packetsintended for at least one TUE over the Uu link and forwarding thepackets onto the at least one TUE over the SL links.

At 1010, a CUE receives configuration information including: anidentification of the TUE that the CUE is to aid by forwarding packetsintended for the TUE; sidelink (SL) transmission resources available tobe used by the CUE for forwarding packets intended for the TUE and forreceiving acknowledgments from the TUE; an identification of initial orredundant transmission signals associated with the CUE and a number ofrepetitions. Additionally, or alternatively, the CUE may receive anidentification of the TUE from the TUE during initial UE cooperationsetup or during a request procedure that the TUE asks for help from theCUE.

At 1020, the CUE receives a packet from the at least one base stationand intended for the TUE.

At 1030, the CUE forwards the packet intended for the TUE, in whichforwarding the packet includes, for up to a maximum number of configuredrepetitions N, n=1 to N, transmitting an nth redundant signal versionhaving a respective modulation and coding scheme (MCS). These parametersfor a SL transmission, such as a maximum number of transmissionrepetitions, each associated redundant version, and a MCS for eachtransmission, can be semi-statically configured via higher layersignaling such as RRC and/or indicated dynamically by SL SCI, asdescribed in previous paragraphs.

At 1040, in an optional step, the CUE receives a positive or negativeacknowledgment of one or more of the repetitions of the packet on aconfigured transmission resource from the TUE.

While flow diagram 1000 describes a process for a single CUE receivingconfiguration information, receiving packets intended for a TUE, andforwarding packets to the TUE, it is to be understood that multiple CUEscould be operating in the same manner for a group of UEs and one or moreof the CUEs could be forwarding to multiple TUEs, if so configured.

While flow diagram 1000 describes a CUE forwarding to a TUE, alternativeembodiments may include the CUE forwarding to a second CUE that iscloser to a TUE than the CUE, and then the second CUE forwarding to theTUE.

FIG. 11 is an example flow diagram 1100 that describes a method how UEcooperation can be performed in accordance with an aspect of thisdisclosure. The flow diagram 1100 involves a UE that is a TUE receivingconfiguration information from a base station, receiving packetsintended for at least one TUE over the SL link, decoding the receivedpackets and sending an acknowledgement to the at least one CUE over theSL links. In some embodiments, to be able to receive forwarded trafficfrom one or more CUEs, the TUE may provide an identification of the TUEto at least one CUE during initial UE cooperation setup or during arequest procedure that the TUE asks for help from the CUE.

At 1110, a TUE receives configuration information including: sidelink(SL) transmission resources available to be used by the TUE forreceiving forwarded packets from the at least one CUE and fortransmitting acknowledgments to the at least one CUE.

At 1120, the TUE receives a packet intended for the TUE, in whichforwarding the packet from a CUE includes, for up to a maximum number ofconfigured repetitions N, n=1 to N, an nth redundant signal versionhaving a respective modulation and coding scheme (MCS).

At 1130, the TUE decodes the packet using one or more receivedrepetitions of the packet from one or more CUEs.

At 1140, in an optional step, the TUE transmits a positive or negativeacknowledgment of one or more of the repetitions of the packet on aconfigured transmission resource.

While flow diagram 1100 describes a process for a single TUE receivingconfiguration information, receiving packets intended for a CUE,decoding the packets and forwarding an acknowledgement of receipt of thepackets to the CUE, it is to be understood that multiple TUEs could beoperating in the same manner and one or more of the TUEs could beforwarding to multiple CUEs, if so configured.

One possible application of sidelink (SL) communications is vehicle toeverything/anything (V2X) communication, for example, which is anincreasingly important new category of communication that may becomewidespread in next generation wireless communication networks, such as5G New Radio (NR) systems. V2X refers to a category of communicationscenarios, including communication from a vehicle to another vehicle(V2V), vehicle to infrastructure (V21), and vehicle to pedestrian (V2P),for example. In general, a vehicle communicating in a network isconsidered user equipment (UE).

The communication in V2X systems may be performed using links betweenthe network and the UE, such as an uplink (UL) and a downlink (DL). TheUL is a wireless communication from a UE to a base station (BS), and theDL is a wireless communication from a BS to a UE. In V2V communicationusing the UL and DL, data is transmitted from a transmitting UE to a BS,and then transmitted from the BS to a receiving UE.

Alternatively, some of the V2X communication scenarios may be device todevice (D2D) communications, in which case the transmission in V2Xsystems may be performed between the transmitting UE and receiving UEusing a sidelink (SL). The SL allows data to be transmitted directlyfrom the transmitting UE to the receiving UE, without forwarding thedata via the BS.

In general, the SL and UE cooperation may enhance the reliability,throughput, and capacity of any wireless communications. However,successful UE cooperation requires proper management of the SL betweenCUEs and TUEs in order to reduce interference and improve UE cooperationbenefits.

It should be appreciated that one or more steps of the embodimentmethods provided herein may be performed by corresponding units ormodules. For example, a signal may be transmitted by a transmitting unitor a transmitting module. A signal may be received by a receiving unitor a receiving module. A signal may be processed by a processing unit ora processing module. The respective units/modules may be hardware,software, or a combination thereof. For instance, one or more of theunits/modules may be an integrated circuit, such as field programmablegate arrays (FPGAs) or application-specific integrated circuits (ASICs).It will be appreciated that where the modules are software, they may beretrieved by a processor, in whole or part as needed, individually ortogether for processing, in single or multiple instances as required,and that the modules themselves may include instructions for furtherdeployment and instantiation.

Although a combination of features is shown in the illustratedembodiments, not all of them need to be combined to realize the benefitsof various embodiments of this disclosure. In other words, a system ormethod designed according to an embodiment of this disclosure will notnecessarily include all of the features shown in any one of the Figuresor all of the portions schematically shown in the Figures. Moreover,selected features of one example embodiment may be combined withselected features of other example embodiments.

While this disclosure has been described with reference to illustrativeembodiments, this description is not intended to be construed in alimiting sense. Various modifications and combinations of theillustrative embodiments, as well as other embodiments of thedisclosure, will be apparent to persons skilled in the art uponreference to the description. It is therefore intended that the appendedclaims encompass any such modifications or embodiments.

What is claimed is:
 1. A method comprising: transmitting, by a basestation, configuration information to at least one cooperative userequipment (CUE) and to a target user equipment (TUE), the configurationinformation comprising an indication of resources for a sidelink (SL)transmission, a redundancy parameter for the SL transmission, and anidentification of the TUE that the at least one CUE is to aid byforwarding the packet intended for the TUE, the SL transmission for theat least one CUE to forward a packet intended for the TUE; andtransmitting, by the base station, the packet intended for the TUE, to aplurality of UEs comprising the at least one CUE, wherein thetransmitting the packet comprises transmitting the identification of theTUE associated with the packet in a higher layer entity.
 2. The methodof claim 1, wherein transmitting configuration information to the atleast one CUE and to the TUE comprises: the base station transmitting tothe at least one CUE: an identification of initial or redundanttransmission signals associated with a specific CUE and a number ofrepetitions; and the base station transmitting to the TUE: anidentification of initial or redundant transmission signals associatedwith the TUE and a number of repetitions.
 3. The method of claim 1,wherein the transmitting the packet comprises one or more of: the basestation transmitting the packet via unicast or group-cast signaling; andthe higher layer entity comprising a layer higher than physical layer,such as packet data convergence protocol (PDCP), radio link control(RLC), or/and Internet Protocol (IP) layer.
 4. A device comprising: aprocessor; and a non-transitory computer-readable medium having storedthereon computer-implemented instructions, that when executed by theprocessor cause the device to: transmit configuration information to atleast one cooperative user equipment (CUE) and to a target userequipment (TUE), the configuration information comprising an indicationof resources for a sidelink (SL) transmission, a redundancy parameterfor the SL transmission, and an identification of the TUE that the atleast one CUE is to aid by forwarding the packet intended for the TUE,the SL transmission for the at least one CUE to forward a packetintended for the TUE; and transmit the packet intended for the TUE, to aplurality of UEs comprising the at least one CUE wherein the transmitthe packet comprises transmit the identification of the TUE associatedwith the packet in a higher layer entity.
 5. The device of claim 4,wherein the instructions further cause the device to: transmit to the atleast one CUE: an identification of initial or redundant transmissionsignals associated with a specific CUE and a number of repetitions; andtransmit to the TUE: an identification of initial or redundanttransmission signals associated with the TUE and a number ofrepetitions.
 6. A method comprising: receiving, by a cooperative userequipment (CUE) from a base station, configuration informationcomprising an indication of resources for a sidelink (SL) transmission,a redundancy parameter for the SL transmission, and an identification ofthe TUE that the at least one CUE is to aid by forwarding the packetintended for the TUE, the SL transmission for the at least one CUE toforward a packet intended for a target user equipment (TUE); receiving,by the CUE, the packet from the base station and intended for the TUE,wherein the receiving the packet comprises receiving the identificationof the TUE associated with the packet in a higher layer entity;forwarding, by the CUE, the packet intended for the TUE, by transmittingup to a maximum number of configured repetitions N, an n^(th) redundantsignal version having a respective modulation and coding scheme (MCS),where n=1 to N and a HARQ identifier (ID) associated with the packet. 7.The method of claim 6, wherein the configuration information comprises:SL transmission resources available to be used by the CUE for forwardingthe packet intended for the TUE; and an identification of initial orredundant transmission signals associated with the CUE and a number ofrepetitions.
 8. The method of claim 6, wherein forwarding the packetcomprises one of: forwarding the packet using one or more repetitions onat least one configured grant transmission resource; forwarding thepacket using one or more repetitions on at least one configured granttransmission resource, together with sidelink control information (SCI)for configuring one or more of: the redundant version signalinformation, forwarding scheme, feedback related info and resourceallocation/indication, CUE/source ID in a UE cooperation (UC) group, TUEID/designation ID in the UC group and MCS; and forwarding the packetusing one or more repetitions on at least one transmission resource thatis dynamically configured, together with sidelink control information(SCI) for configuring one or more of: the redundant version signalinformation, an HARQ ID associated with the packet, diversity scheme,forwarding scheme, TUE ID/designation ID in the UC group and MCS.
 9. Themethod of claim 6, further comprising the CUE receiving a positive ornegative acknowledgment of one or more of the repetitions of the packet:on a configured grant transmission resource; or on a transmissionresource that has been pre-configured or dynamically configured.
 10. Adevice comprising: a processor; and a non-transitory computer-readablemedium having stored thereon computer-implemented instructions, thatwhen executed by the processor cause the device to: receiveconfiguration information, from a base station, comprising an indicationof resources for a sidelink (SL) transmission, a redundancy parameterfor the SL transmission, and an identification of the TUE that the atleast one CUE is to aid by forwarding the packet intended for the TUE,the SL transmission for the device to forward a packet intended for atarget user equipment (TUE); receive the packet from the base stationand intended for the TUE, wherein the receive the packet comprisesreceive the identification of the TUE associated with the packet in ahigher layer entity; forward the packet intended for the TUE, bytransmitting up to a maximum number of configured repetitions N, ann^(th) redundant signal version having a respective modulation andcoding scheme (MCS), where n=1 to N and a HARQ identifier (ID)associated with the packet.
 11. The device of claim 10, wherein theconfiguration information comprises: SL transmission resources availableto be used by the device for forwarding the packet intended for the TUE;and an identification of initial or redundant transmission signalsassociated with the device and a number of repetitions.
 12. The deviceof claim 10, wherein the instructions further cause the device toforward the packet by one of: forwarding the packet using one or morerepetitions on at least one configured grant transmission resource;forwarding the packet using one or more repetitions on at least oneconfigured grant transmission resource, together with sidelink controlinformation (SCI) for configuring one or more of: the redundant versionsignal information, forwarding scheme, feedback related info andresource allocation/indication, CUE/source ID in a UE cooperation (UC)group, TUE ID/designation ID in the UC group and MCS; and forwarding thepacket using one or more repetitions on at least one transmissionresource that is dynamically configured, together with sidelink controlinformation (SCI) for configuring one or more of: the redundant versionsignal information, an HARQ ID associated with the packet, diversityscheme, forwarding scheme, TUE ID/designation ID in the UC group andMCS.
 13. The device of claim 10, wherein the instructions further causethe device to receive a positive or negative acknowledgment of one ormore of the repetitions of the packet: on a configured granttransmission resource; or on a transmission resource that has beenpre-configured or dynamically configured.
 14. A method comprising:transmitting, by a target user equipment (TUE), an identification of theTUE to at least one cooperative user equipment (CUE); receiving, by theTUE, configuration information originating from a base station,comprising an indication of resources for a sidelink (SL) transmissionand a redundancy parameter for the SL transmission, the SL transmissionfor the at least one CUE to forward a packet intended for the TUE;receiving, by the TUE, the packet intended for the TUE, the packetcomprising, for up to a maximum number of configured repetitions N, n=1to N, an nth signal version having a respective modulation and codingscheme (MCS) and a HARQ identifier (ID) associated with the packet; anddecoding, by the TUE, the packet using one or more received repetitionsof the packet from one or more CUEs.
 15. The method of claim 14, whereinthe configuration information comprises at least one of: SL transmissionresources available to be used by the TUE for receiving packets; anidentification of initial or redundant transmission signals associatedwith the TUE and a number of repetitions; and a diversity scheme to beused for transmission by the TUE.
 16. The method claim 14, whereinreceiving the packet comprises one of: receiving the packet as one ormore repetitions on at least one configured grant transmission resourcefrom one or more CUEs; receiving the packet as one or more repetitionson at least one configured grant transmission resource from one or moreCUEs, together with sidelink control information (SCI) for configuringone or more of: the redundant version signal information, diversityscheme, forwarding scheme, TUE ID/designation ID in a UE cooperation(UC) group and MCS; and receiving the packet as one or more repetitionson at least one transmission resource that is dynamically configuredfrom one or more CUEs, together with SCI for configuring one or more of:the redundant version signal information, an HARQ ID associated with thepacket, diversity scheme, forwarding scheme, TUE ID/designation ID inthe UC group and MCS.
 17. The method of claim 16, further comprising theTUE transmitting a positive or negative acknowledgment of one or more ofthe repetitions of the packet on the configured grant transmissionresource.
 18. A device comprising: a processor; and a non-transitorycomputer-readable medium having stored thereon computer-implementedinstructions, that when executed by the processor cause the device to:receive configuration information, originating from a base station,comprising an indication of resources for a sidelink (SL) transmission,and a redundancy parameter for the SL transmission, the SL transmissionfor at least one cooperative user equipment (CUE) to forward a packetintended for the device; receive the packet intended for the device, thepacket comprising, for up to a maximum number of configured repetitionsN, n=1 to N, an nth signal version having a respective modulation andcoding scheme (MCS) and a HARQ identifier (ID) associated with thepacket; and decode the packet using one or more received repetitions ofthe packet from one or more CUEs.
 19. The device of claim 18, whereinthe configuration information comprises at least one of: SL transmissionresources available to be used by the TUE for receiving packets; anidentification of initial or redundant transmission signals associatedwith the TUE and a number of repetitions; and a diversity scheme to beused for transmission by the TUE.
 20. The device of claim 18, whereinthe instructions further cause the device to receive the packet by oneof: receiving the packet as one or more repetitions on at least oneconfigured grant transmission resource from one or more CUEs; receivingthe packet as one or more repetitions on at least one configured granttransmission resource from one or more CUEs, together with sidelinkcontrol information (SCI) for configuring one or more of: the redundantversion signal information, an HARQ ID associated with the packet,diversity scheme, forwarding scheme, TUE ID/designation ID in a UEcooperation (UC) group and MCS; and receiving the packet as one or morerepetitions on at least one transmission resource that is dynamicallyconfigured from one or more CUEs, together with SCI for configuring oneor more of: the redundant version signal information, an HARQ IDassociated with the packet, diversity scheme, forwarding scheme, TUEID/designation ID in the UC group and MCS.
 21. The device of claim 20,wherein the instructions further cause the device to transmit a positiveor negative acknowledgment of one or more of the repetitions of thepacket on the configured grant transmission resource.